1. Field of Invention
This invention relates to a pneumatic device for use in sealing a tubeless tire to a wheel rim.
2. Description of Related Art
When a tubeless tire that is to be inflated is fitted onto a wheel, typically the beads of the tire do not seal against the wheel rim. Accordingly, when pressurized air is supplied to the valve stem of the wheel, the air escapes from the inside of the tire through the space that exists between the beads of the tire and the wheel rim, making it difficult to inflate the tire. This problem is even more acute with larger sized tires/wheels, for example, those used on trucks and heavy-duty earth moving equipment, due to the increased weight and dimensions of the tires. Since such tires usually are inflated while in a horizontal orientation, the uninflated tire sags, which increases the size of the space through which air escapes. Numerous methods and tools have been developed in an attempt to solve the above described problem.
One method entailed igniting ether within the tire. The resulting explosion usually would temporarily seal the beads of the tire to the wheel rim so that the tire could be inflated. This technique is dangerous and has led to the death of individuals.
It is also known to apply a soapy liquid to the beads of the tire to assist in sealing the tire beads to the wheel rim. This technique is not always successful, particularly on larger tires. It also results in the interior of the tire becoming coated with the soapy liquid, which can make it difficult to apply a patch to the interior of the tire if the tire should become punctured during normal use.
Pneumatic tire sealers have been developed to rapidly inject air into the tire, between a bead of the tire and the wheel rim, so as to seal the beads of the tire to the wheel rim.
Some of these tire sealing devices require the user to place a ring-shaped tubular member around the circumference of the space formed between a bead of the tire and the wheel rim. Examples of pneumatic tire sealing devices having curved tubular members are shown in U.S. Pat. Nos. 3,552,469; 3,683,991; 3,814,163; 3,851,695 and 5,247,982. While these devices seal the beads of a tubeless tire onto a wheel rim, they are not easily adaptable to different sized tires or rims. These devices also can require a substantial amount of time in the preparation of the equipment prior to the sealing process.
Other devices for injecting air into a tire between a bead of the tire and the wheel rim are disclosed in U.S. Pat. Nos. 4,744,402; 5,056,576; 5,072,765; 5,168,911 and 5,456,302. These devices are expensive, bulky (and therefore not readily portable--and certainly not a "handheld" device) and cumbersome to use.
U.S. Pat. No. 5,570,733 to Desparois et al. discloses a hand-held tool for inflating tires. The tool includes an injection head for directing a valve controlled, large volume, high pressure jet of air into the cavity of a deflated tire. The tool includes an ON/OFF valve that is biased to the OFF position for safety purposes and also includes clips (posts) to assist in positioning the tool on the wheel rim. Although the ON/OFF valve provides a limited safety function, it does not prevent over-inflation of the tire. The clips do not hold the tool and the rim together, and therefore fail to prevent the tool from being inadvertently propelled away from the wheel (and toward the user) when the burst of air is discharged from the tool, which could lead to injury.
U.S. Pat. No. 3,866,654 to Duquesne discloses a device for inflating tubeless tires. The device provides a conventional tire inflating hose for attachment to the tire valve during inflation. However, the device lacks a multi-directional nozzle and its design leaves open the possibility of the nozzle becoming stuck between the tire and rim, thereby preventing a complete seal. The device also suffers from all of the disadvantages discussed above with respect to U.S. Pat. No. 5,570,733.
U.S. Pat. No. 5,072,764 to Ochoa discloses a device for sealing tubeless tires using a hand operated valve for releasing a blast of air from a storage tank. The device has a pressure limiting valve, but only limits the pressure in the tank and not the tire, leaving the tire exposed to possible overpressurization.